Toward the implementation of quantum key distribution with cold atomic quantum memories *

Quantum key distribution (QKD) is a quantum technology designed to encrypt sensitive information in an era where increasing computation power poses a threat on classical encryption methods. As a branch of Quantum Information Science, QKD has had a significant advance toward its practical implementation. At the Quantum Technologies Laboratory of the Center for Research and Advanced Studies (Laboratorio de Tecnologías Cuánticas, CINVESTAV, Unidad Querétaro), we seek to implement a complete quantum communication network based on QKD that includes elements such as quantum memories as repeater nodes, allowing the storage and retrieval of information encoded in quantum states of light.

Quantum optical memories are crucial devices on quantum communication and computation that can store and retrieve quantum states of light  demand. In this work, we are interested in generating efficient quantum memories in large atomic ensembles of Rb-87 in atomic vapor as well as cooled in magneto-optical traps. As the first part of this project, we are developing and improving the actual simulations of quantum storage of light in alkali atomic ensembles with the dynamical electromagnetically induced transparency. Moreover, we are also interested in investigating the reversible transfer of entanglement between light and quantum memories based on the DCLZ protocol.